SoCalMule 106 Posted February 18, 2019 Sure could use some advise guys... I have found fiberglass muffler packing "plugs" collecting right behind the spark arrester screen on my 450 exc, way too many times. I even road the bike for a few weeks without the screen, thinking that it will just blow out the residual fiberglass (from the fresh repack that was completed 10-15 hours ago). Did I somehow pack the muffler wrong? Maybe I put too much masking tape on to hold the packing in place for ease of reassembling it? I would take the muffler apart... but man, I did such a good job of sealing the muffler with heat rated silicone! Anyone else have had this kind of issue? Is it normal for a fresh repack to shed for a bit? My previous bikes did not have a spark arrester screen system like this one has. The photos show a collection of fiber after an 80 mile desert ride. Thanks for any help, The Plugged Mule Share this post Link to post Share on other sites
simicrintz 177 Posted February 18, 2019 That plug appears to be about the size of a quarter (I am assuming inflation bore its ugly head and only a dime was available!). I'll ask the stupid question: why did you repack? Is this something that needs to be done occasionally? Unfortunately I have questions and not answers. Share this post Link to post Share on other sites
SoCalMule 106 Posted February 18, 2019 43 minutes ago, simicrintz said: That plug appears to be about the size of a quarter (I am assuming inflation bore its ugly head and only a dime was available!). I'll ask the stupid question: why did you repack? Is this something that needs to be done occasionally? Unfortunately I have questions and not answers. It’s been my experience that to keep optimum performance for the engine that occasionally we should re-pack our mufflers. When a muffler becomes too loud it’s usually a sign that the packing is in need of replacement. One interesting thing is that even with my muffler partially blocked my KTM still puts out a lot of horsepower. I just noticed a performance drop during high demand throttle positions. Share this post Link to post Share on other sites
kkug 145 Posted February 18, 2019 Sheared off when you were assembling the muffler ? Share this post Link to post Share on other sites
amgems 79 Posted February 18, 2019 Hey Mark, I think your gonna have to take it apart to find out what's up. Some things to look for: Could be something not lined up correctly. Maybe a broken weld. Maybe the perforated tube has split or has a hole in it. That's quite a bit of packing. I think the stock mufflers use o rings to seal the caps. Share this post Link to post Share on other sites
simicrintz 177 Posted February 18, 2019 I learn something new every day! Guess I will be repacking one day. Mine does have an O ring (took it apart to check it out one day and learned I had to make sure it went back in right!). Share this post Link to post Share on other sites
SoCalMule 106 Posted February 18, 2019 Just now, kkug said: Sheared off when you were assembling the muffler ? Thanks kkug, i don’t think that’s it... I was very carfull not to force anything during assembly. This seems to be more like the exhaust gas is creating a resonance and it’s just blasting the insides of the packing out of the muffler and the fibers end up collecting fiber by fiber at the screen. Share this post Link to post Share on other sites
SoCalMule 106 Posted February 18, 2019 17 minutes ago, amgems said: Hey Mark, I think your gonna have to take it apart to find out what's up. Some things to look for: Could be something not lined up correctly. Maybe a broken weld. Maybe the perforated tube has split or has a hole in it. That's quite a bit of packing. I think the stock mufflers use o rings to seal the caps. Thanks Jim, I agree with you. Was hoping it would just stop on it’s own; that someone had it happen and would say “no problem Mark, just ride it!” Share this post Link to post Share on other sites
Bagstr 287 Posted February 18, 2019 Must be the front end open OR packing is too fine and migrating thru screen. Second install is always better. Share this post Link to post Share on other sites
SoCalMule 106 Posted February 18, 2019 19 minutes ago, Bagstr said: Must be the front end open OR packing is too fine and migrating thru screen. Second install is always better. That sounds possible Dave. I will dive in to it in the morning. I have a new packing kit that has a separate sock that goes over the screen pipe inside before I wrap it. This should fix it! Thanks so much! I'll post pics of what I find. Share this post Link to post Share on other sites